We applied Latent Class Analysis (LCA) to responses to items from the Activism and Radicalism Intentions Scales (ARIS). In two studies (undergraduates n = 530) and prisoners (n = 670), item profiles identified four groups - Inert, Moderate Activists, Strong Activists, Radicals, and Mixed - that confirm and extend the levels of the Action Pyramid of the Two Pyramids Model of Radicalization. Radicals were a higher proportion of prisoners than undergraduate respondents (20% vs. 12%), and, among prisoners, Radicals were more likely than other groups to be gang members. The distinction between Moderate and Strong Activists is a surprising addition to the literature of political radicalization, and we suggest in the Discussion that the study of Activists, and comparison of Activists and Radicals for the same cause, deserve more attention.
